A virtual globe is a 3D software model or representation of the Earth or another world. A virtual globe provides the user with the ability to freely move around in a virtual globe by changing a viewing angle and position. One popular program that allows users to navigate a virtual globe is “The Google Earth” client developed by Google, Inc. (Mountain View, Calif.).
The Google Earth client offers a user a high-performance, virtual fly-through experience of a virtual globe's imagery and terrain. Google Earth annotates this imagery and terrain with feature labels denoting cities, islands, mountains etc. As the user “flies around” in Google Earth, labels appear at different levels of scale, depending upon the significance of the geographic feature. For example, a label for the capital city, Paris, will appear at a larger scale (“zoomed-out”) than a small hamlet in upstate New York.
When zoomed-out to a scale where many features are visible, users may desire to see feature labels without icons or other placemarks to minimize visual clutter, providing the user with a familiar “map-like” view. The user, however, may also be interested in learning more about a geographic feature (e.g., an island) marked by a feature label, and would like to have easy and immediate access to content related to the feature (e.g., Web content).